Machines for manufacturing wire netting and the like



April 19, 1960 P. M. R. BOWER 2,933,109

MACHINES FOR MANUFACTURING WIRE NETTING AND THE LIKE Filed Nov. 1, 1955 5 Sheets-Sheet 1 Inventor WWW Qgwlu/ Em April 19, 1960 P. M. R. BOWER 2,933,109

MACHINES FOR- MANUFACTURING WIRE NETTING AND THE LIKE Filed Nov. 1, 1955 5 Sheets-Sheet 2 W B m April 19, 1960 P. M. R. BOWER 2,933,109

ACHINES FOR MANUFACTURING WIRE NETTING AND THE LIKE Filed Nov. 1, 1955 5 Sheets-Sheet 3 April 19, 1960 P. M. R. BowER 2,933,109

MACHINES FOR MANUFACTURING WIRE NEJTTING AND THE LIKE Filed Nov. 1, 1955 5 Sheets-Sheet 4 Atlornev! April 19, 1960 P M. R. BOWER 2,933,109

MACHINES FOR MANUFACTURING WIRE NETTING AND THE LIKE 5 Sheets-Sheet 5 Filed NOV. 1, 1955 United States Patent MACHINES FOR MANUFACTURING WIRE NETTING AND THELIKE Paul M. R. Bower, Wroxham, .Barnards 'Limited of Norfolk Norfolk, England Application November 1, 1955, Serial No..544,337 Claims priority, application Great Britain June 6, 1955 9 Claims. (Cl. 140---'6) England, assignor 'to Iron Works, Norwich,

are then divided, the adjacent strands of adjacent pairs being brought. together at a second twisting-mechanism where the strands are similarly twisted. round each other. The strands are then separated and reformed intoltheir original pairs and again similarly twisted. This procedure is repeated continuously to form a length of netting.

Each twisting mechanism consists of a number of twisting heads arranged in a straight line across the machine, there being two or more lines of such twisting heads which become operative alternately or in endless succession to perform successive twisting operations. The twisting heads in one line are staggered with respect to those in an adjacent line so that each twisting head is opposite a gap between adjacent heads. In this way, wire netting is formed with the twists on one row staggered by half a mesh with respectto those in an adjacent row, giving the familiar hexagonal mesh pattern.

It. is an object of the present invention to provide an improved mechanism for making wire netting by the reverse twist method;

Another object of the invention is to provide means for ensuringthe accurate feed-in of the strands to their appropriate twisting heads...

l Another object of the invention is the provision of feed-in mechanism which will obviate anytendency for two strands to jam when enteringa twisting head.

A further object of the inventionis a feed-in mechanism which alternately inverts the strands of each pair with respect to; each other and to the adjacent strand of thenext pair as the; strands are fed into successive twisting heads so that theorderof engagement of any one-strand with respecttoits co-operating strand in suc- .cessive heads is reversed Astill further objectofi: the, invention is a mechanism for automatically imposinga :dwell on each twistinghead during boththe feed-in and take-off periods.

. Yet anotherobjectof the invention is a common drive for. all the twisting-heads comprising a worm which meshes with worm-wheel .teeth on eachhead and is rotated relatively thereto, and mechanism synchronised with the main drivefor imparting axial displacements to the worm jin alternately opposite directions, the displacement in one. directionserving to exactly neutralise .the drive-actionof theworni to produce a dwell-at all the twisting heads during a feed-in-and take-oftperiod.

Other objects and features of the invention will become apparent from the following particular description, given by way of example only, ofalternative practical embodiment thereof, reference bemg made to the accompanying drawing wherein:

Figure l is a sectional side elevation. on the hue I--I of Figure 2;

Figure 2 is a fragmentary plan view on the arrow 11 of Figure 1, parts of the main drive being shown in sec. tion whilst the worm displacement mechanism and repetitive parts of the capstan, twisting, and take-off drums are omitted for clarity;

Figure 3 is a composite part-sectional view, to a larger scale, and generally similar to Figure 2, of the worm dis-- placement mechanism, the upper half showing the worm in one limit position of its axial displacement whilst the lower half shows the worm in its other limit position of axial displacement;

Figure 4 is a fragmentary part-schematic view of. a twisting head at the end of a dwell period;

Figure 5 is a view similar to Figure 4 showing the twisting head after it has made a quarter revolution;

Figure 6 is a fragmentary section through the separator tube in one limit position of its oscillation; I

Figure 7 is a view similar to Figure 6 showing the separator tube in its other limit position;

Figures 8 and 9 are generally schematic fragmentary views illustrating the two successive pairings of four strands, and corresponding respectively to the positions of the separator tube shown in Figures 6 and 7;

Figure 10 is a detail view, on a larger scale, of a pair of, strands in a twisting head after twisting has been completed;

Figure 11 is a general view of a section of wire mesh produced by the machine, and l I igure. 12 is a view similar to Figure 1 showing a modified strand feed-in device Referring first more particularly to Figures 1-3, the machine comprises a pair of end frames 1 in which are journalled a capstan drum or roller 2, wire guide and tension rollers 3, a twisting drum 4, a take-oif drum or roller 5, and an oscillatory separator tube 6. An automatic stop assembly is mounted at the top of the machine, andconsists of a number of separate levers 7 (Figure 1) -one for each warp strand of wire 8-- pivoted on a cross bar 9 and carrying at their rear ends respective pulleys 10 over which individual strands 8 are passed from the capstan roller 2 and the guide and tension rollers 3; The opposite ends of the levers 7 are engaged by compression loading springs. 11 mounted on guide pins 12 secured in a commonangle bar 13. Fracture of a warp strand 8 causes pivotal movement of its associated lever 7 under the action of the spring 11, and this in turn operates a conventional mechanism for stopping the machine.

The twisting drum 4 has six sets of pinions 14 mounted iii-slots 15 at equal angular pitches around its circumference, the axes of these pinions lying tangential to the circumference whilst the pinions themselves project through the slots 15 r to mesh with a common driving worm '16 mounted coaxially within the drum 4. The worm 16 is both rotated and reciprocated axially in synchronism with thedrum rotation in such a way that all the pinions 14 are alternately held stationary-when the axial displacement is exactly equal to the pitch of theworm and of opposite sense theretoand then to tated at twice the speed which corresponds to the worm pitch andifor a whole number of revolutions. This mechanism will be described later. 1

Each pinion '14 has a radial slot 14a (Figures4land 5') extending from its centre to its circumference, the

slot being of a width such that a strand of wire 8 can I i just enter it without binding. The alternate stationary Each pinion 14 is located between the opposed noses 17a (Figures 4 and 5) of a pair of spheroidal segments 17, these segments being secured to the surface of-the twisting drum 4 in six longitudinal rows and the segments of each row being symmetrical about a generatrix of the cylindrical surface of the drum 4. Each pinion 14 and its associated pair of segments 17 constitutes a twisting head. The function of each pair of segments 1-7 is to pick up an adjacent pair of warp wires 8 and guide them into the slot 14a in the respective pinion 14 so that they can be twisted together by the rotation of the pinion, one wire lying on top of the other in the pinion slot, as seen in Figures 4 and 5. The gap be tween the noses 17a of each pair of segments 17 is aligned circumferentially with the maximum-radius back edges'17b of the adjacent segments 17 of two pairs in the next row, the latter two segments being assembled close together back-to-back with a gap between them suflicient to allow a Selvedge wire 8c (to be described be- 1 low) to pass between them. Each back edge 17b of a segment 17 lies in a plane normal to the axis of the twisting drum 4, and the planes containing adjacent edges 17b lying on opposite sides of a similar plane which contains the axes of pinions 14 in the adjacent rows of twisting heads. This arrangement is more clearly illustrated in Figures 8 and 9, where P and Q can be regarded as the edges of the planes. containingthe said p n on axes.

The separator tube 6 has two diametrically opposed rows of holes each aligned along a generatrix of the tube surface. The holes of each row are of two diameters, those of larger diameter, 18, alternating with those -l 4 cam follower roller 22 rides on the crest of the lobe (Figure -6),'whilst as pairs of wires are being fed into the slots in the next set of pinions 14 the follower roller 22 rides in the trough between adjacent lobes (Figure 7). The separator tube 6 thus oscillates between two limit positions of angular deflection each of which is occupied when wires are being fed into the slots of a set of pinions 14.

The operation ofthe separator tube 6 is as follows. Assuming that the tube is in one limit position of. oscillation and considering first a pair of warp wires 8a, 8b being fed into one pinion 14, one of these wires (say, 8a) :enters-the separator tube through a larger diameter hole 18 and emerges through a smaller diameter hole 19, whilst the-other wire-8b enters through a small hole 19 and emerges thr ough a large hole 18, see Figures 8 and9.

The diametral plate T (Figures 6 and 7) of the tube 6 containing the axes O of the two rows of holes 18, 19 is at an angle to its mean position, which will be assumed to be tangential 'to the-twisting drum 4 and is substantially coincident with the wire 8b of Figure 6 or Saof'Figure 7. -As seen in Figure 6, the smaller out 4 let holes- 19 are below this mean tangential plane, and

the smaller-inlet holes 19 are therefore above it. These relative positions are reversed in Figure 7. The wire 8a emerging from the separator tube 6 through a small hole 19 will be deflected downwards, as seen in Figure 6. The otherwire-Sb of the pair under consideration, however, emerges from a large hole 18, and since it enters the separator tube 6-through an elevated small hole 19, it willemerge from a point near the upper portion of the large hole 18. When the separator tube 6 makes '1 its next half-oscillation, however, the relative positions of smaller diameter, 19 (see Figures 2 and 6-9), whilst the larger holes 18 in one row is coaxial with a smaller hole 19 in the other row. Each wire 8 passes through one such pair of coaxial holes from the tensioning pulleys 10 to the twisting drum 4. The common axis of each pair of coaxial holes 18, 19 lies mid-way between two planes which are both normal to the twisting drum axis, the one plane containing the axis of a pinion '14 inone row (and also the radial slot 14a thereof when the said slot is receiving a pair of wires prior to twisting) whilst the other plane contains the axis of, and

the radial slot 14a in, another pinion 14 in the next ro'w, so that a wire 8 passing through the said pair of holes in the separator tube 6 is deflected-by successive oppositely facing segments 17 alternately towards its neighbour on one side or the other as the twisting drum rotates and brings successive rows of segments into the wire-engaging position.

Figures 8 and 9 illustrate the relative alignments of the axes O of successive pairs of holes 18, '19 in the separator tube 6 and the axes P, Q respectively of pinions 14 in adjacent rows along the drum 4. a

In order to ensure that the two wires 8 of a pair to be twisted are laid one upon the other in proper order as they enter the slot in a given pinion 14, it is nece s sary that one segment of the operative pair should engage its respective wire earlier than the other segment, so'th'at the first wire is deflected towards the pinion before the other. latory separator tube 6.

This result is achieved by the oscillines) earlier than the upper wires 8a.

of the wires 8a, 8b in what may be regarded as the up and down direction will "be reversed, as shown in Fig ure 7.

At the same time as the wires 8a, 8b are being deflected (up and down with respect to each other by the oscillation of the separatortube 6, they are also being mutually deflected laterally bygthe action of the spheroidal segments 17. The wire 8a of Figure 6 is not only lower than the wire 8b with which it will pair at the next twisting head 14, but will strike the oncoming segment 17 at a larger angle to the axis 0 than that at which the wire 8b willstrike its oncoming segment. This condition is shown in Figure 8, where the point of contact of each wire 8a with its respective oncoming segment 17 (shown in chain lines) is marked x, whilst the corresponding points for the wires 8b are marked y. Hence, the wires 8a is lower down thecurved feed-in surfaces of the segments 17 at any given instant during the half-cycle of the tube 6 represented by Figure 6 than the wires 8b, and so enter the slots 14a in the pinions 14 first. Figures 4 and 5 show this relative positioning of the wires.

When the half-cycle of Figure 7 occurs, however, the relative conditions are reversed, and Figure 9 shows the now lower wires 8b deflected by their segments 17 (chain positions of the pairs in their slots 1411 are thus reversed. In either half-cycle, therefore, one wire of a pair 8a, 8b is deflected into the slot 14a before the other. It will be appreciated that Figures 6-9 are purely schematic for the purpose of illustrating the principle of operation of The separator tube 6 is mounted in bearings 20 (Figure I -2) at each end, and has secured to'one end thereofa the separator tube 6 and segments 17.

Selvedge wires 80 are also fed through the machine at the sides of the web of mesh being made, these wires following a different path from the main warp wires 8.

7 The wires 80 wrap around respective tensioning pulleys 10 (Figure 1) in the reverse sense from the main warp wires 8 and arelled through separate guide holes 24 in a transverse bar '25. The holes 24 are directly aligned with the gaps between the noses 17a and backs 17b of adjacent segments 17 (see Figure 2). Thus theselvedge wires 8c,d0 not become deflected by the segments, and

The relative f'einain straight throughout the process exceptwhere they are twisted together with a warp wire The mechanism for driving the pinions 14of the twisting heads will now be more particularly described with reference to Figure 3. As shown in Figure 3, a face cam 26 is provided on one end of the drum, Follower rollers 27 are mounted on a spider 28 which is mounted on the worm shaft 29 and in which the said shaft is free to rotate. The spider 28 is constrained from rotating by an anchorage (not shown) to the frame 1 which nevertheless permits it to move longitudinally. The follower rollers 27 are sandwiched between the cam face 26 'and a disc 30 freely mounted on the shaft 29, and are kept in contact with both the face cam 26 and the disc 30 by a. spring 31; this spring surrounds the shaft 29 and is arranged between a stop 32 fixed to the-drum shaft 29 and a thrust bearing 33 on the shaft.

-The pinions 14 are removably mounted in their. bearings so that they can be removed for cleaning or changing by removal of the segments 17.

The drum '4 is preferably removably arranged in the machine so that the machine may be used for netting of different sized meshes.

The pitch of the worm 16, the lift of each lobe of the cam 26, and the ratio of the gearing coupling, the drum 4 and the worm shaft 29 in the gearbox 34 (Figure 2.) can;be arranged to give the required number of twists to the wires.

In operation of the machine, the shaft 29 and the drum 4. are. rotating continuously at different speeds. so that the pinions 14 would normally rotate. During feed-in of the strands 8 and take-off of the twisted mesh the pinions must remain stationary, and for. this purpose the cam 26 moves the worm shaft 29 longitudinall-yiin .the drum 4.

This shaft movement is such that, were the worm 16 not rotating, the pinions 14 would be rotated at the same angular velocity as, but in the opposite sense to, that at which they would be driven by the worm 16 if the latter were rotated without axial displacement. Hence, thetwo component rotary motions of the pinions 14 cancel each other during feed-in and take-off so that the pinions remain stationary with respect to the twisting drum 4. Figure 4 shows the positions of the parts during such a dwell period, the cam 26 and rollers 27 being shown formalised, and the directions of motion being indicated by arrows.

When, by rotation of the drum 4, the portions of the wires 8 to be twisted are positioned in the pinion slots 14a,the cam 26 is timed to move the worm shaft 29 within the drum back to its original position, thus rotating the pinions at double the speed which would otherwise be imparted to them by rotation alone of the worm 16, to twist the pairs of Wires together in a double twist. The gear ratios are preferably such that the pinions 14 make two complete revolutions for each twisting movement, but they may be arranged to make a greater number of twists if desired. The commencements of a twisting operation is shown in Figure 5, which illustrates the roller 27 on the opposite flank of the cam 26, and the direction of axial displacement of the worm 16 reversed as compared with Figure 4.

Figure 12 shows an alternative wire feed-in arrangement to the separator tube 6 described above. This alternative consists of a rigid bar 125 having one row of holes 24 for the selvedge wires Be (as in Figures 1 and 2) and a second row of holes 118 for the strands 8a and 8b to I be twisted. In the form of wire feed device, reliance is placed on the degree of offset of the axes of the holes 118 from the axes P and Q of Figures 8 and 9 to obtain the correct sequence of feed of the wires 8a, 8b of a pair into each slot 14a in a twisting head 14. This modified arrangement, though simpler than the oscillatory tube 6, has been found less reliable in use in avoiding jamming of the strands in a slot 14a.

Various detail modifications of design can be made 6 without departing from the scope of the invention, as will be understood. For example, the oscillatory motion of the separator tube can be derived from an independent drive synchronised with the drive to the twisting drum.

I claim:

1. In a machine for making twisted wire netting of the kind in which pairs of wire strands are twisted together by the rotation of slotted pinions journalled on a rotary twisting drum, the combination. of a worm co axial with the drum and freely rotatable therein to mesh with all the twising pinions simultaneously; means for rotating the drum and the worm at difierent speeds and means for axially reciprocating the worm through one complete cycle during each complete twisting cycle of the twising pinions, the axial displacement of the worm during one half-cycle of its reciprocation being such as to exactly neutralise the rotation imparted to each pinion by virtue .of the relative rotation of the worm and the drum so as to impart a dwell period to the pinions while their radial slots are facing radially outwards from the surface of the drum.

2. In a machine for making twisted wire netting in whicheach pair of warp strands is twisted together by a slotted pinion journall'ed in a rotary twisting drum between a pair of opposed upstanding generally. partspheroidal wire-deflecting segments, the provision .of a worm mounted coaxially within said drum for relative rotation and axial displacement therein, said worm meshing with all the pinions: means for driving said worm and said drum at predetermined relative speeds to cause rotation of the pinions: andmeans for axially reciprocat ing said worm through a complete cycle during each, cycle of operation of a row of twisting heads, the axial displacement of the worm during one half cycle of its reciprocation being such as to neutralise the rotation which would otherwise be imparted by the worm to the pinions.

3. A machine for making twisted wire netting inwhieh the pairs of warp strands are twisted together by a P111? rality of slotted pinions journalled in a rotary twisting drum between pairs of opposed upstanding generally part: spherical wire-deflecting segments, including a worm mounted co-axially within said drum for relative rotation and axial displacement therein, said worm meshing with all the pinions; means for driving said worm and said drum at predetermined relative speeds to cause rotationof said pinions and means for axially reciprocating said worm through a complete cycle during each cycle of operation of a row of twisting heads, the axial displacement of the worm during one half cycle of its reciprocation being such as to neutralise the rotation which would otherwise be imparted by the worm to the pinions, and including means for feeding warp strands: to the twisting pinions comprising a separator tube mounted in bearings with its axis parallel to that of the worm; two sets of wire guide holes in said separator tube, each set lying on a generatrix of the tube surface and both said generatrices lying in a diametral plane containing the'axis of the tube; each set further consisting of alternate large and small diameter holes, a large hole in one set being coaxial with a small hole in the other set; and means for oscillating said separator tube in its bearings about a mean position in which said diametral plane is substantially tangential to the surface of the twisting drum, said oscillating means being synchronised with the means for reciprocating the worm so that said tube is ina limit position of its oscillatory motion during a half-cycle of reciprocation of the worm when the pinions are stationary.

4. A machine as claimed in claim 3 wherein the separator tube oscillating means comprises a cam geared to the worm drive and a follower arm secured to the separator tube and engageable with the cam.

5. A machine as claimed in claim 2 wherein the worm is mounted on a shaft which extends beyond one end of the drum and the means for reciprocating the worm comtewe prises a follower arm mounted on said shaft extension withoutlfreedomiofrelative axial displacement thereon; a driven "by the twisting' drumz and spring means for biasing the follower armint'o contact with the cam, the cam having a lobe each flank of which lies at an angleto the axis of the worm shaft such that the latter is' displaced through one worm pitch per revolution as the follower rides on each said flank.

:6. A machine as claimed in claim 2 and having a worm shaft carrying the worm and extending beyond one end of the twisting drum: a cam follower arm jour nailed on the worm shaft and restrained against rotation therewith; means for transmitting axial thrust to the shaft from the armpajface 'carn surrounding said shaft extension and having'alobe whose flanks are inclined to the worm shaft axis at an angle such that the axial displacenient of the worm due to the riding of the follower on either lobe flank is proportional to the worm pitch in a ratiod'ependent'on the desired number of complete revolutions of each pinion during a warp strand twisting operatwisting pinion operating mechanism comprising a singl worm. meshing continuously and simultaneously with all the pinions; means for continuously rotating the worm to drive-thepinions; and means for axially reciprocating said worm during its rotation the speed of displacement during alternate half-cycles of reciprocation being equal to and in the opposite sense from, the eifective feed of the worm thread, whereby the pinions remain stationary for a dwell period during the feed-in of pairs of warp strands of wire to be twisted together during the intervening' half-cycles of reciprocation of the worm.

tion'thereof; a disc mounted on the worm shaft extension the opposite side of the follower arm from the cam; and spring loading means on the worm shaft for urging the disc against the follower arm and the latter against the '7. A reverse twist wire netting making machine having a twisting drum carrying a plurality ofequiangularly spaced rows of radially slotted twisting pinions and ineluding a common driving worm meshing with all said pinions internally 'of said twisting drum and mounted coaxially Within the drum with freedom of rotation and axial reciprocation relative thereto:' and a cam and follower mechanism interconnecting the twisting drum and the worm for eifecting said axial reciprocation ofthe worm relative to the drum, the cam having a lobe one flank of which is so proportioned that, during engagement of the follower therewith, the worm is axially displaced within the drum through a distance and with a uniform speed, such that each pinion in a row remains stationery for a dwell period sufficient to allow a pair of warp strands to enter its radial slot in a predetermined sequence while twisted strands are removed from each pinion in another row.

8. In a reverse-twist wire netting making machine,

9 In a reverse-twist wire netting-making machine, twisting pinion operating mechanism comprising a single worm meshing continuously and simultaneusly with all theipinions; means for continuously rotating the worm to drive the pinions; and means for axially reciprocating said worm during its rotation the speed of displacement during alternate half-cycles of reciprocation being equal toJand in the opposite sense from, the eflective feed of the worm' thread;'whereby the pinions remain stationary for a dwellperiod. during the feed-in of pairs of warp strands of wire tohe twisted together during the intervening -half-cycles' of reciprocation" of the worm, in combination with wire feed mechanism comprising an oscillatory tube extending parallel to the Worm axis and pierced with two rows of holes whose axes lie in a cominon diametral plane ofthe tube, the holes of each row being of alternately large and small diameter whilst'a large diameter hole of either row is coaxial with a small diameter hole of the other and means for oscillating said tube synchronism with the reciprocation of the worm so that each limit position of oscillation about a mean position, in which said diametral plane substantially includes the axes of a row of pinions, coincides with a dwell period of said pinions.

' References Cited in the file of this patent UNITED STATES PATENTS 2,544,838 Kitselman Mar. 13, 1951 

